Abstract
Background/AimThe aim of this study was to compare volumetric-modulated arc therapy (VMAT) radiation plans between conventional VMAT with flattening filter (cFF-VMAT) and flattening filter-free VMAT (FFF-VMAT) for localized prostate cancer.Materials and methodsTen patients with localized prostate cancer who underwent cFF-VMAT at Yokosuka General Hospital Uwamachi, Yokosuka, Japan, from July 2020 to October 2020 were enrolled. Dose-volume histogram (DVH) parameters of the target volume, normal organs, monitor units (MU), and beam-on time (BOT) were compared between cFF-VMAT and FFF-VMAT plans.ResultsNo significant difference was observed for DVH parameters for the target volume. No significant difference was observed in all parameters for the bladder and rectum between the cFF-VMAT and FFF-VMAT groups. The mean values of MU were 686 ± 52 and 784 ± 80 in cFF-VMAT and FFF-VMAT, respectively (p < 0.001). The mean BOT was 97.0 ± 6.6 s and 72.9 ± 1.4 s for cFF-VMAT and FFF-VMAT, respectively (p < 0.001).ConclusionDVH parameters of the target volume and normal organs were not significantly different between the cFF-VMAT and FFF-VMAT plans. In FFF-VMAT, MU was significantly higher, and the BOT was significantly shorter than those in cFF-VMAT.
Highlights
Prostate cancer is the second most common cancer worldwide and the fifth based on mortality rate [1]
No significant difference was observed in all parameters for the bladder and rectum between the cFF-volumetricmodulated arc therapy (VMAT) and Flattening filter-free (FFF)-VMAT groups
A study of multiple treatment sites revealed that D2 and homogeneity index (HI) of planning target volume (PTV) were significantly higher in FFF-VMAT than those in cFF-VMAT, but they were negligible [29]
Summary
Prostate cancer is the second most common cancer worldwide and the fifth based on mortality rate [1]. Radiation therapy (RT) is one of the radical treatment modalities for localized or locally advanced prostate cancer. Favorable treatment outcomes have been reported by escalating the radiation dose [2,3,4,5]. Development of radiotherapy techniques, such as intensity-modulated radiotherapy (IMRT) and volumetricmodulated arc therapy (VMAT), can deliver dose escalation to the target volume without increasing the toxicity to surrounding normal organs [2]. Hypofractionated RT with a higher dose fraction was expected to demonstrate a favorable therapeutic effect. Several randomized controlled trials on the use of hypofractionated RT for prostate cancer have been conducted and found to be comparable to the conventional fractionated RT [13,14,15]. Irradiation time generally becomes longer in hypofractionated RT. Intrafractional motion has been found to be increased as the irradiation time becomes longer [16]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
